JP3917590B2 - High compression filter tow veil and its manufacturing process - Google Patents

Abstract

Disclosed is a packed, highly compressed cuboid-shaped filter tow bale, the top side and bottom side of which are free from nuisome curvatures or constrictions. Said bale is characterized by the fact that a) the bale has a packing density of at least 300 kg/m<3>, b) the bale is entirely wrapped in a mechanically self-supporting, elastic packing material which is provided with one or several convectively airtight connections, and c) the top side and bottom side of the bale are so flat that a flat plate which fully covers the bale can be pressed onto the top side of the bale via a centrally effective normal force of 100 N and at least 90 percent of the surface of the top side of the bale, which lies within the largest rectangle that can be inserted by vertically projecting the bale onto the pressed plate, has a maximum distance of about 40 mm from the flat plate when the unopened bale is placed on a horizontal plane. A particularly suitable method for producing said bale comprises the following steps: a) filter tow is supplied in a compressed form; b) the compressed filter tow is enveloped in a wrapping; c) the wrapping is closed in an airtight manner; and d) the wrapped bale is relieved of the load. The wrapping of such a bale is largely prevented from bursting as a result of the prevailing internal pressure. The inventive bale has an ideal cuboid shape such that curvatures negatively affecting the bale during transport or constrictions hampering the behavior of the filter tow are largely prevented from occurring.

Description

  The present invention relates to a bale of a filter tow that is packed and highly compressed into a block form, and which has no constricted expansion or constriction at the top or bottom of the bale, and a manufacturing process thereof.

  In the manufacture of filter tows for use in filter rods in the tobacco industry, the tows are placed in so-called filling containers or cans. During this process, the filter tow is distributed in a uniform layer over the cross-sectional area of the container by the movement of the arrangement unit which moves alternately in the full length direction and the cross direction. As a result, multiple layers can be stacked on top of each other until the filter tow package reaches the desired weight and height in the container. In this range, a package weight of several hundred kilograms is normal. WO 02 / 32,238 A2 describes a highly compressed bale and a process for optimizing the container in order to avoid problems with the resulting process.

Next, the contents filled in the container by this method are compressed in the direction of overlapping the layers. After this compression, the filter tow package is packaged by the packaging material, still in the compression device and thus under compressive stress. The press is then fully opened and the filter tow package, now called the “bale”, is put together by the packing material. Conventional packaging includes cardboard that is mechanically bundled together with straps or adhesives, such as synthetic fabric that is closed by hook- and- loop fasteners . An example of a glued package is described in German Utility Patent No. 76-35,849.1. Information on filter-toe packaging wrapped in synthetic fabrics is available at Engusserstrasse 8, D-79108, a company letter of intent “Some Useful Information about the Reusable Packaging for Rhodia” published by RHODIA Acetow Co. Filter Tow "(" some useful information about reusable packaging of Rhodia filter tows "). In the latter two types of packaging, no additional straps are required.

  For packages of the type described above that do not use any straps, the direction in which the bale is compressed due to the elastic restoring force of the compressed filter tow after the pressure applied to the bale has been released at the end of the press operation. The problem is that pressure in the opposite direction is applied to the packaging. This increases the capacity of the package and causes undesired expansion at the top and bottom of the bale. When the measurement described in WO 02 / 32,238 A2 is performed, the use of the target filter tow is not hindered by these expanded parts, but the safe stacking of the filter tow package is hindered. End up. This problem can be solved by state-of-the-art technology, such as that described in the Rhodia publication cited above, where the bale is stacked on its side or a special pallet is used. In addition, problems associated with rupture opening of packages due to continuous internal pressure frequently occur.

  A solution to problems associated with straps is described in US-A 4,577,752. When the filter tow packed with the strap was used as intended, the expansion portion had a smaller problem than the constricted portion that caused a change in the expansion resistance described in WO 02 / 32,238 A2. In addition, even a bale with a strap will burst open. Further, in packing a filter tow, it is standard to use an inner liner between the filter tow and the above-mentioned mechanically supported packing material. The inner liner protects the filter tow from contamination, particularly odor contamination, and prevents water vapor from spreading inside and outside the package. Usually, the inner liner is composed of three parts arranged in close contact with the interior of the outer package.

  An object of the present invention is to provide a high-compressed filter toe bale in an ideal block configuration without an inflated portion that hinders the movement of the bale and a constricted portion that impedes the feeding of the filter tow at the top and bottom of the tow bale. In this case, the load applied to the packed filter tow is reduced, and in particular, the burst opening of the package under the influence of the internal pressure can be almost completely avoided. A further object of the present invention is to provide a packaging process associated therewith.

  These objects are achieved according to the invention by a bale in the form of a filter tow block according to claim 1 and a process according to claim 14.

That is, the present invention
(A) the bale has a packing density of at least 300 kg / m ³ ;
(B) the bale is completely packaged with a mechanically self-supporting elastic packaging material, which material comprises one or more coupling parts that are airtight to convection;
(C) When a flat plate is pressed on the top of the bale with a force of 100 N acting in the vertical direction on the center of the bale in a state where the unopened bale is arranged on a horizontal plane, the bale perpendicular to the pressure plate Within the largest rectangle inscribed in the projection, the top and bottom surfaces of the bale are flat so that at least 90% of the portion of the top surface of the bale located within the inscribed rectangle is separated from the flat plate by about 40 mm or less. It is a bale of a filter tow that is packed and highly compressed in the form of a block, having no hindered expansion or constriction on the top or bottom of the bale.

The drawbacks associated with the movement of packages that are commonly used today have already been mentioned in the state of the art description above. It is the inflated parts, particularly at the top and bottom of the bale, that impede movement in the two layers. This problem has been solved in the past by moving the bale in a sideways storage position rather than a so-called working position. However, to do so, it is necessary to add two more work steps: a step of rotating the bale by 90 ° before moving, and then a step of returning to the working position after moving. In addition, the constriction formed by the strap is a source of problems. Even when the bale is used as intended, these constricted portions can cause considerable changes in the expansion resistance of the filter rod made of filter tow. These changes affect more than 5% of the filter rods made with veils. The higher the packing density of the bale, the greater the severity of these two problems. Problems arise as soon as the packing density exceeds 300 kg / m ³ .

  After a series of failure experiences, it is surprising that a bale in the form of a block can be produced without any obstructing part that hinders movement or constriction that obstructs the use of the intended filter tow, by hermetically sealing the package during the packaging process. The discovery that should be done. Thus, based on practical considerations, the bale according to claim 1 is fully packaged with a mechanically self-supporting elastic packaging material, which is a tightly bonded to one or more convections Department.

  With preliminary and superficial analysis, the bale according to the present invention may be thought of as a vacuum-packed bale, and therefore a vacuum package that every consumer knows from experience every day. But this is not the case. The goal achieved with the block form bale according to the present invention is to create a clear form. The challenge of hermetic packaging is to absorb and equalize the pressure gradient that occurs at the top and bottom of the bale during the manufacturing process. It has been found that there is no need to impose any further requirements on the packaging relating to its mechanical strength, air permeability, moisture content, etc. Instead, it has been found that the veil according to the present invention can maintain its properties even when perforated over a wide range of previously airtight materials after the packaging process. Based on practical considerations, such additional measurements are not performed.

  The outline of the veil according to the invention is represented by the feature (c) of claim 1. For example, the distance from the plate to each point on the top surface of the bale can be determined by using a transparent plate and measuring the reflection to determine the distance between each point and the plate. Alternatively, any other continuous distance measuring method can be used. Within the scope of the principles of the present invention, 90% of the range of the top surface of the bale located within the aforementioned inscribed rectangle is spaced from the flat plate by a distance not exceeding about 25 mm, preferably not exceeding about 10 mm. Is particularly preferred.

In relation to the packing capacity of the bale, it is advantageous to have a bale capacity of 0.9 m ³ or more and / or a packing density higher than 350 kg / m ³ , in particular less than 800 kg / m ³ Is known. It has also been found that it is particularly appropriate to form the veil in the form of a block having a height of at least about 900 mm, preferably about 970 mm, in connection with mounting the package in a container. In this case, the veil can be laminated in two layers in the container. Since such blocks can be arranged in individual stacks in the container, packed blocks with a height of 970 to 1,200 mm are particularly preferred. Furthermore, it is possible to produce a veil that is much higher than this in order to reduce the packing operation for the amount of fibers to be packed. When the packaged material is a filter tow, these large packages are advantageous because the number of bale changes is very low when the filter is used to manufacture tobacco filters with a filter rod machine.

  The package wrapping material is preferably made of a plastic film. The connection that is airtight to convection is formed by a seam that is impermeable to convection air, which is designed as a heat-sealed lap or seam (uberlappende Siegel-oder Flossennaht) And is advantageous.

  The film is preferably made of polyethylene, especially LDPE, modified polyethylene (LLDPE), or a laminated film comprising a polyamide layer and a polyethylene layer. Colored or printed films can be used as packaging films for advertising and aesthetic purposes. This is particularly recommended when the filter tow being packaged is photosensitive. In addition, an adhesive label that provides information about the contents of the package, for example, can be attached to the film. Another possibility for transmitting information to the package is to engrave a relief that can be seen through a film that adheres to the surface of the package by negative pressure. In addition to the name of the product, the relief may include a company and / or customer logo. The film preferably has the property of becoming a highly reliable packaging material for transportation. This is the reason why a film having a thickness of 100 to 400 μm is used. If desired, a transport package such as cardboard, synthetic fabric, etc. can be placed around the film after packaging the package or after sealing the film itself, i.e., after the block form bale has been completed. Thereafter, straps can be applied to the shipping packaging. As a result, the mechanical stability of the packaging is increased, allowing the use of thinner and thus less expensive films. However, this type of shipping packaging is not essential within the scope of the present invention.

The process of packing the filter tow veil according to the present invention is as follows:
(A) converting the filter tow into a compressed form;
(B) wrapping the compressed filter tow with a package wrapping material;
(C) hermetically sealing the package packaging material;
(D) releasing a load applied to the packaged bale.
When the load on the hermetically sealed bale is released, negative pressure is generated in the package. This negative pressure is preferably at least 0.01 bar, and in a particularly advantageous manner is in the range from 0.15 to 0.7 bar.

  Therefore, the negative pressure generated in the region surrounded by the packaging material can be maintained by the hermetic seal of the packaging material. This negative pressure attenuates the pressure applied from the inside to the package by the elastic restoring force of the flexible material. For this reason, the expansion that normally occurs in the filter tow veil can be prevented according to the state of the art. This makes it much easier to manufacture laminated veils. Because the mechanical pressure acting from inside the package is attenuated (by negative pressure), the risk of failure of the package or the tendency of the package to tear down is reduced. In addition, higher packing densities are also obtained, which provides the advantages of smaller packages and allows for reduced storage and transfer capacity. In particular, according to this method, the storage capacity of the container for storing the filter tow packed in this way can be optimally used.

  Providing a compressed form of filter tow is typically accomplished using conventional pressing equipment. In the process according to the present invention, first, a filter tow for the purpose of packaging is mechanically compressed in a press apparatus, and then packaged with a package packaging material. In this case, the package wrapper is sealed while still in the press. This embodiment provides the advantage that the entire process can be completed in one place.

  Furthermore, it is possible to compress the filter tow elsewhere as a preparatory step. In this case, the pre-compressed filter tow is provided with an “auxiliary packing”, for example with a holding clamp, after which the filter tow is sent to the packing place, where the auxiliary packing is removed and the compressed filter tow It is packaged with a package packaging material, a negative pressure is generated, and the package packaging material is hermetically sealed. This embodiment provides the advantage that the pressing device can be equipped with higher functionality since the entire process is not completed in place. Furthermore, the delay of the pressing cycle is reduced and the compressed bale can be reached from all sides at the packing site, increasing the degree of freedom gained in connection with the addition of package wrapping material.

  Contrary to the state of the art, the use of the process according to the present invention eliminates the need for an inner liner to protect the bale from contamination and water vapor, since the packaging material used as a package serves an alternative function.

  The negative pressure required mainly in the process according to the present invention can be generated by various methods. According to a particularly simple embodiment, the negative pressure is generated by expanding a compressed filter tow material. After the filter tow in a compressed state is packaged with a package wrapping material and hermetically sealed, the external pressure applied to the packaged material is released. As a result, inside the package, the material expands under the action of its own elastic restoring force. By increasing the capacity of the package, negative pressure is generated within the range surrounded by the packaging material. The size of the package is such that the compressed filter tow cannot be fully expanded, i.e. the filter tow inside the wrapping material remains compressed to a certain degree inside the package after its partial expansion. It is preferable to select. This embodiment has the advantage that it is not necessary to add a means for generating a negative pressure. Therefore, the cost can be particularly reduced.

  According to another embodiment, which can be used as an alternative or addition to the application forms described above, negative pressure is generated by evacuation from the inner region surrounded by the packaging material. With this method, it is possible to obtain a higher vacuum than the “natural” vacuum described above. Furthermore, the desired negative pressure can be adjusted with high precision by this method.

  The evacuation can be performed, for example, by means of one or more vacuum pumps. These vacuum pumps are first connected to the inside of an airtight package which is airtight except when connected to the vacuum pump on the intake side, and then operated. After reaching the desired negative pressure, the pump is disconnected from the package and the exhaust connection site provided in the packaging material is hermetically sealed again.

  The combination of the two embodiments described above provides the advantage that the vacuum time can be reduced because the negative pressure is obtained by two different measurements that can be performed simultaneously. In addition to this, a higher packing height can be selected, so that the required compression force is lower. The term “packing height” in this case refers to the height of the filter tow bale after it is hermetically sealed in the device used to compress the filter tow. Finally, according to this method, the height of the filter tow veil can be adjusted with excellent precision. As a result, it is possible to mitigate external influences particularly related to season, titer, weight and the like.

  In the process according to the present invention, it is preferable that a negative pressure of about 0.15 bar to 0.7 bar lower than the ambient pressure is generated. This corresponds to an absolute pressure of about 0.85-0.3 bar within the film-wrapped volume. Thus, the vacuum in question is in the “low vacuum” range, which is usually completely sufficient for the process of the present invention. A negative pressure of about 0.2 to 0.4 bar, which corresponds to an absolute pressure of about 0.8 to 0.6 bar, has proven particularly suitable. The selection of the negative pressure fixed range depends on various parameters, in particular the type and amount of the packed material, the desired packing density, the packaging material used, etc. It should be noted that in principle, the stronger the vacuum or negative pressure, the smaller the package is obtained. An increase in negative pressure also has an effect of reducing expansion. However, it should also be considered that selecting a higher vacuum unduly increases the time required to achieve the desired negative pressure.

  As far as the packaging material used in the process according to the invention is considered, this ensures that the desired negative pressure generated over time and the desired mechanical stability of the packaging are assured. Must be selected. The desired stability over time usually varies between days to months, and even years, depending on the type of material being packaged and the method used for it. Therefore, it is possible to use films having different air permeability.

  According to certain embodiments, it may be desirable to be able to use polyethylene or improved polyethylene films such as LLDPE or LDPE for packaging materials. LDPE is a low-density polyethylene that is purified at high pressure, and LLDPE is a name for a low-density polyethylene having a linear structure. This type of plastic film has the advantage that it is a pure material and can be manufactured at low cost. However, since a single piece of polyethylene is not strong enough, this is particularly suitable for materials packaged at a relatively low packing density and low capacity. Standard polyethylene film is more suitable for use when storage time does not exceed several weeks due to its relatively high air permeability.

  Alternatively, a laminated film made of polyamide and polyethylene can be advantageously used as a package packaging material. This lamination is characterized by very low air permeability and high strength, which means that the negative pressure can be kept constant over a long period of time. It is preferred that the polyamide layer occupies about 1/3 of the laminate and the polyethylene layer occupies about 2/3.

Gas permeability of the air in the package wrapping material or film, preferably ^{10,000cm 3 / (m 2 · d} · bar) below, also preferably ^{200cm 3 / (m 2 · d} · bar) , more preferably less than 20 cm ³ / (m ² · d · bar). These values are measured according to DIN 53,380-V at 23 ° C. and 75% relative humidity. In this case, it is ensured that the vacuum lasts for a sufficient time and that the package is kept as small as possible without loosening. In addition, this range is covered with standard commercial films (eg PA-PE laminate). It should be emphasized that air is not moved by convection through the film, but mass transfer only occurs by diffusion throughout the film. These values represent the permeability ambient air (N ₂ has approximately 78% O ₂ is about 21%, other gases 1%) are based on similar composition. The only important values are those related to oxygen and nitrogen permeability. Furthermore, in addition to the film, it is possible to use other airtight materials that satisfy the above-mentioned conditions within the scope of the present invention.

The water vapor transmission rate of the film or another packaging material is preferably less than 5 g / (m ² · d), preferably when measured at 23 ° C. and 85% relative humidity according to DIN 53,122, part 2. It is less than ² g / (m ² · d). The permeability of water vapor is not related to the function caused by the form of the packaging, but the product water content of the filter tow is maintained by such packaging due to the packaging that is impermeable not only to air but also to water vapor. The advantage of continuing is obtained. This is very important in the case of filter tows. As a result, a uniform water content can be obtained throughout the bale, and humidity exchange with the surrounding environment does not occur. A 100 μm thick polyethylene film has a water vapor transmission rate of about 1 g / (m ² · d).

  With respect to mechanical strength, the package wrapper or film has a tear strength of at least about 10 N / 15 mm, preferably about 100 N / 15 mm or more, more preferably 200 N / 15 mm or more, as measured according to DIN EN ISO 527-3. It is recommended to have Each quoted value relates to a minimum tear strength value in the machine and transverse directions of the film. As a function of whether the film-wrapped bale is re-packed for transfer, a specific choice related to tear strength is made. In this connection, usable materials include PE with a thickness of 15 to 30 N / 15 mm at a thickness of 100 μm, PA6 with a thickness of 150 to 300 N / 15 mm at a thickness of 100 μm. It is.

  In general, plastic films with an air barrier layer such as polyamide, polyester, or ethylene vinyl alcohol copolymer (EVOH), or metal oxide coated materials such as coatings such as SiOx, aluminum oxide, etc. And aluminum foil have been found to be particularly advantageous. However, this list of films is not considered complete. In addition, these are advantageous for various types of packaged materials because the film provides air impermeability, odor protection, i.e. protection against external odor ingress. Specific strength is important in order to mechanically stabilize the film. This property is obtained in particular with polyamides.

  One available method for hermetically sealing the package wrapper or film is to weld or heat seal it. Therefore, a film that is preferably weldable or heat sealable should be selected. In this connection, the preferred film material is a material with a low melting point. Examples thereof include polyolefins such as polyethylene and polypropylene, or polymers of ethylene and propylene such as EVA and LLDPE. In the following description, a material that satisfies the conditions of weldability or heat sealability is referred to as a “sealing layer”. The film can consist of only this type of sealing layer, or it can consist of a laminate consisting of one or more sealing layers and additional layers designed to provide, for example, mechanical strength. .

  In order to ensure that the package can be opened easily, the sealing layer can be “peelbar”, ie sealed in a heterogeneous form. This type of heterogeneous seal layer can be manufactured in various ways, such as adding polybutylene to the seal layer at some point, or sealing polypropylene against LLDPE. Another way to facilitate the opening process is to provide a tear strip on the packaging film. This method is particularly for low strength films. Finally, a protrusion angle or the like may be provided, and this may be cut off when the package is opened. When the protrusion angle is cut off, air can flow into the package, thereby loosening the package. Thereafter, if the film is cut using a film cutting knife, the package can be opened without damaging the package contents.

  Alternatively, the package wrapper or film can be sealed with an adhesive. This embodiment provides the advantage that a heat sealing device is not required. Of course, other suitable packaging film sealing methods can be used as long as they provide the desired properties related to leakage prevention and the mechanical tensile strength required for the scope of concern. It is.

  Heat sealing or welding can be accomplished, for example, in such a way as to form an overlap seam. Overlapping seams can absorb relatively high tensile forces, so that even when just packed, the packaged material can be tightly packed, and even if there is a leak in the package, A complete elastic restoring force can act on the packaging from the inside. Therefore, this type of closure is very safe and in this case it is recommended to provide a heat seal layer on both sides of the film (or to make up the film with only such a heat seal layer).

  According to another embodiment, welding or heat sealing can be accomplished with a method of forming a fin-like seam known to those skilled in the film processing art. This provides the advantage of being easy to manufacture from the outside, but the ability of such a seam to withstand tensile stress is lower than that of an overlapping seam.

  The package wrapper or film can be designed in the form of a one-piece bag, for example. In this case, the prepared filter tow is packaged by a method similar to the method of packaging one candy. Alternatively, the film can be constituted by a bottom portion, a top portion, and a peripheral collar. In this case, since it is necessary to join each part, the whole length of a joint seam is extended. According to another preferred embodiment, a film / packaging consisting of a top and a bottom can be manufactured before use, that is, deep drawn or formed into a bag, etc. It is also possible to cut the film into two parts that interlock like a tennis ball. Furthermore, other suitable methods for designing the film / packaging may be used within the scope of the present invention.

  If desired, after the final seal of the package wrapping material or film, i.e., the completion of the film and packaging, the bale can be repackaged with cardboard, synthetic fabric, etc. disposed around the film. This increases the mechanical strength of the packaging so that a thinner and therefore less expensive film can be selected. However, it is emphasized that this type of repacking is not essential within the scope of the present invention.

  When external repackaging is used as described above, the negative pressure can be equalized in relation to the ambient pressure within 1-2 days by deliberately designing to reduce the airtightness of the film / packaging It is possible to In other words, during this period, the package “loses” suction. This allows the packed filter tows to expand into the external packaging, but the swelling formed at the top and bottom of the package is less noticeable than the filter tows packed according to a state-of-the-art process. Not something.

  The thickness of the film used in the process according to the present invention is about 100 to 400 μm, and the range of 200 to 300 μm, especially 250 to 300 μm is optimal. The exact thickness of the film used is selected as a function of the size and weight of the fiber material to be packed, the degree of compression, i.e. the packing density, and the type of material used. As already mentioned above, it is possible to select a somewhat thinner film when using additional external packaging, in particular cardboard external packaging.

  Therefore, the compressible filter tow to be packed is manufactured in a particularly optimal block form. As a result, a package is obtained that is particularly easy to stack and handle and that is easier to store. As already explained in connection with the state-of-the-art process, it is preferred that the cable-like filter tows are arranged in layers on top of each other.

  The present invention will now be described in more detail based on preferred embodiments with reference to the accompanying drawings.

  A bale of compressible, flexible and fibrous material 1, in this case a filter tow, is wrapped with a film 2 and introduced into a pressing device 3, as shown in FIG. For example, the bale is compressed to a desired packing height in the press device 3 capable of applying a pressure of about 300 to 400 tons. Thereafter, the film 2 is hermetically sealed leaving a small range that functions as a connection point with a suction hole of a vacuum pump 4 such as a sliding blade rotary pump. Next, the inside of this range wrapped with the film 2 is evacuated by the vacuum pump 4 until a desired negative pressure is obtained. When this desired negative pressure is reached, the vacuum pump hose is disconnected from the film and the connection point is hermetically sealed. As described above, the use of the vacuum pump can be omitted when the desired negative pressure level is small enough to be obtained, for example, by expansion of the bale.

  In the next step shown in FIG. 1b, the processing device 3 is opened. This causes the bale to expand again to the extent permitted by the size of the film / packaging. The filter tow bale after packing has been removed from the press and is ready for movement and storage as shown in FIG. 1c. The height of the packed bale depends on various factors including the strength of the vacuum generated.

  Figures 2a and 2b show another stage of the process according to the invention, i.e. providing an optional outer packaging 5 to the packed filter tow veil. This can be provided especially for the purpose of movement, and can be composed of, for example, lightweight cardboard. Since these types of external packaging materials are known to those skilled in the art, a detailed description is omitted here.

FIGS. 3a and 3b show graphs representing the change over time of the properties of the package produced by the process according to the invention based on the use of a polyethylene film, a film laminated with polyethylene and polyamide. The polyethylene film of FIG. 3a has a gas permeability of about 600 ml / (m ² · d · bar), whereas the laminated film of FIG. 3b has a gas permeability of about 10 ml / (m ² · d · bar). Only. As can be derived from the comparison of the two graphs, the negative pressure generated in the case of the laminated film, as well as the height of the veil, remains essentially uniform over several hundred days. On the contrary, the negative pressure in the case of a bale wound with polyethylene film has already decreased by half after a few hundred days, while the height of the bale has increased by more than 10 cm over the same period. If the veil is stored for 2 years or more, the cost is higher, but a laminated film is preferred.

  As can be seen in FIG. 4a, it is possible to reduce the height of the bale by increasing the vacuum strength. In the figure, three different curves are shown. The top curve shows the height of the bale that can be achieved without using a vacuum pump as a function of packing height. The middle curve shows the result of adding an additional 0.1 bar vacuum and the bottom curve shows the result of adding an additional 0.1 bar vacuum. A type 3Y35 filter tow with a bale weight of 580 kg was treated at a pressure of 370 tons. Under these conditions, an additional vacuum of 0.1 bar can easily be generated in about 60 seconds.

  FIG. 4b shows the height of the bale under altered environmental conditions as a function of the strength of the additional vacuum, where the air temperature is about 40 ° C. and the ambient air pressure is About 0.05 bar higher than the example. It can be seen that the height of the bale increases at lower air pressure and higher temperature.

  In the illustrative embodiment described above, a laminated film of polyethylene and polyamide having a thickness of about 200 μm was used. The film was heat sealed manually using a sealing device, with the collar portion bonded to the top and bottom elements that were preconditioned during pressing. In all cases, the processing power was 370 tons. By the processing means according to the present invention, packing and cost can be greatly reduced.

  According to another example, a bale with the same weight and a packing height of 900 mm was wound with a laminated film of polyamide and polyethylene, which was then welded closed. After opening the press, the tow veil height was 970 mm. No expansion was seen in any part of the packed bale. Due to the increased air volume in the bale, a negative pressure of 0.12 bar corresponding to an absolute pressure of 0.88 bar is obtained. This negative pressure was obtained without using a vacuum pump.

  In another embodiment, a bale of the same weight and a packing height of 900 mm was wrapped with a laminated film of polyamide and polyethylene, which was then welded closed. The inside of the package was evacuated to a negative pressure of 550 bar corresponding to an absolute pressure of 450 bar by means of a vacuum pump. The height of the tow veil that opens the press apparatus has increased to about 930 mm. The pressure inside the package was calculated to be 0.42 bar corresponding to a negative pressure of 0.58 bar. Again, there was no expansion in any part of the packed bale.

Each step of embodiment of the process concerning this invention is shown. Each step of embodiment of the process concerning this invention is shown. Each step of embodiment of the process concerning this invention is shown. Fig. 3 shows a complex form of package obtained by the process of the present invention. Fig. 3 shows a complex form of package obtained by the process of the present invention. 2 shows a graph representing the change over time in the properties of a package obtained by the process of the invention using a polyethylene film. Fig. 3b shows a graph of a laminated film of polyethylene and polyamide similar to Fig. 3a. Figure 5 shows various curves illustrating the relationship between packing height and tow veil height for various negative pressures. Figure 5 shows various curves illustrating the relationship between additional vacuum and tow veil height at higher temperatures and reduced air pressure.

Claims (26)

No expansion portion or constricted portion such that the interference to the top side and the bottom side of the bale, packaged, a bale of filter tow high compression in block form,
(A) the bale has a packing density of at least 300 kg / m ³ ;
(B) the bale is completely packaged in a mechanically self-supporting elastic packaging material , the material comprising one or more connecting parts that are airtight to convection;
(C) a non-opened state bale while placed on a horizontal surface, is pressed against a flat plate on top of the bale, when brought into a force of 100N in a vertical direction with respect to the center of the bale, bale against pressure plate The top surface of the bale to the extent that at least 90% of the portion of the top surface of the bale located within the inscribed rectangle is spaced about 40 mm or less from the flat plate within the largest rectangle inscribed in the vertical projection of And the bottom is flat;
(D) the bale has a height of at least about 900 mm;
(E) at least 0.01 bar negative pressure is applied to the bale relative to the external pressure after at least the bale is packed;
Filter tow veil characterized by that.   The bale of claim 1, wherein the bale has a tear strength (measured according to DIN EN ISO 527-3) of at least about 10 N / 15 mm. Bale according to claim 1 or 2, characterized in that it has a packing capacity higher than 0.9 m ³ and / or a packing density of 350 kg / m ³ , in particular less than 800 kg / m ³ . 4. Bale according to any one of claims 1 to 3, characterized in that it has a height of at least 970 mm, in particular 970 to 1200 mm. The bale according to any one of claims 1 to 4 , wherein the package wrapping material is a film, particularly a plastic film. The bale according to any one of claims 1 to 5 , wherein the connection part having airtightness to convection is a seam through which convection air cannot pass. The bale according to claim 6 , wherein the seam which cannot transmit air is an overlap heat seal seam or a fin-like seam. 90% of the top surface of the bale which is located the inscribed inside rectangle, 2 5 mm or less, preferably characterized in that away from said flat plate at a distance of 1 0 mm or less, of the preceding claims The bale according to any one of the above. 9. Bale according to any one of claims 5 to 8 , characterized in that it consists of polyethylene, in particular LDPE, or modified polyethylene (LLDPE).   The bale according to at least one of claims 5 to 8, wherein the package packaging material is a laminated film in which a polyamide layer and a polyethylene layer are laminated. The bale according to any one of claims 1 to 10 , wherein the package wrapping material has a thickness of about 100 to 400 µm. With additional mobile packing the bale consists of cardboard or synthetic fabric and / or veil according to any one of claims 1 to 11, further being packaged in the strap, characterized in that. 13. A bale according to at least one of the preceding claims, characterized in that a negative pressure of at least about 0.01 bar with respect to the external pressure present after the packaging is released. (A) preparing the filter tow in a compressed form;
(B) wrapping the compressed filter tow with a package wrapping material;
(C) sealing the package wrapping material in an airtight state ;
(D) releasing the load on the packaged bale;
(E) 0 is also the least with respect to external pressure. Generating a negative pressure of 01 bar in the packaging material from which the load has been released,
In particular the process of packaging the veil filter tow according to any one of claims 1 to 13. 15. The process of claim 14 , wherein the negative pressure is generated by natural expansion of the compressed filter tow. 16. Process according to claim 14 or 15 , characterized in that the negative pressure is generated by exhausting air. The process of claim 16 , wherein the air is exhausted with the aid of a vacuum pump. 18. Process according to any one of claims 14 to 17 , characterized in that a negative pressure is produced that is about 0.15 to 0.7 bar lower than the ambient pressure. 19. The process of claim 18 , wherein a negative pressure is generated that is about 0.2-0.40 bar lower than the ambient pressure. It said package packaging materials, welding or by heat sealing, the process according to any one of claims 14 to 19, characterized in that it is sealed in such a way as to form a seam or fin seam was particularly superimposed. A film having a water vapor transmission rate of 5 g / (m ² · d) or less, preferably 2 g / (m ² · d) or less at a temperature of 23 ° C. and a relative humidity of 85% measured according to DIN 53, 122 is used as a package packaging material. 21. Process according to any one of claims 14 to 20 , characterized in that it is used as A film having a gas permeability of 10,000 cm ³ / (m ² · d · bar) or less as measured in accordance with DIN 53,380-V at a temperature of 23 ° C. and a relative humidity of 75% is used as a packaging material. The process according to any one of claims 14 to 21 , characterized in that: ^{2 00cm 3 / (m 2 ·} d · bar), according to claim 22 Preferably, characterized by using a film having a ^{2 0cm 3 / (m 2 ·} d · bar) following gas permeability as a package wrapping material The process described in Least be 1 0N / 15 mm, in particular least be 1 00N / 15 mm in裂破strength claims, characterized by using a film having a (measured according to DIN EN ISO 527-3) as the packaging wrapping material 14 24. The process according to any one of 23 . The process of claim 24 wherein the裂破strength, characterized in that a least be 2 00N / 15 mm (measured according to DIN EN ISO 527-3). The process The process of any one of claims 14 to 25, characterized in that the packing density of the least be ³ 00kg / m 3 is controlled so as to obtain.

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